A369391 Number of nonempty subsets of {1..n} whose elements have a square average.

1, 1, 1, 2, 4, 10, 20, 26, 31, 35, 41, 63, 143, 399, 1083, 2554, 5078, 8596, 12772, 17222, 21792, 27126, 36538, 62530, 146701, 412191, 1178071, 3156949, 7703823, 16992539, 33946851, 61840501, 103674983, 161604395, 236759149, 330078718, 446073360, 606337592

Offset

1,4

Links

Alois P. Heinz, Table of n, a(n) for n = 1..200

Example

a(5) = 4 subsets: {1}, {4}, {3, 5} and {3, 4, 5}.

Crossrefs

Cf. A051293, A126024, A309160, A339454, A357355.

Sequence in context: A083844 A026554 A259132 * A099413 A328761 A271624

Adjacent sequences: A369388 A369389 A369390 * A369392 A369393 A369394

Keyword

nonn

Author

Ilya Gutkovskiy, Jan 22 2024

Extensions

a(24)-a(38) from Alois P. Heinz, Jan 22 2024

Status

approved